This document discusses collations in MySQL 8.0. It begins with an introduction to Unicode and why it is important for databases. It then defines character sets, encodings, and collations. New features in MySQL 8.0 include a default character set of utf8mb4 and many new language-specific collations. Migrating to MySQL 8.0 may require altering tables, schemas, and columns to take advantage of the new collations while considering issues like changed collation rules and index sizes.